FCC Grants ARRL’s Request for Temporary Waiver for TDMA Systems

Acting upon a subsequent request by the ARRL, the FCC issued an Order (WT Docket No, 12-283) on March 25, granting a temporary waiver to transmit communications on amateur service channels above 30 MHz using single time-slot Time Division Multiple Access (TDMA) systems. The temporary waiver was granted pending the resolution of a related rulemaking proceeding (RM-11625).

Currently, amateur stations are authorized to transmit messages using telephony and data emissions. The ARRL noted in its request that Amateur Radio Service licensees have recently established numerous narrowband repeater facilities using multiple time-slot TDMA repeaters and single-slot TDMA handheld digital transceivers in the 70 centimeter (420-450 MHz) band, but Part 97 as it currently stands does not permit amateur stations to transmit single-slot TDMA emissions on Amateur Radio Service channels above 30 MHz.

The FCC stated in its Order that the purpose of specifying emission designators for the Amateur Radio Service “is to relegate the transmission of certain inharmonious emission types to different segments of the frequency bands, while still allowing great flexibility in the types of emissions that may be transmitted by amateur stations.” In granting the temporary waiver, the FCC agreed with the ARRL, noting that the digital systems that radio amateurs have recently implemented are “compatible with existing amateur repeater channelization plans.”

The FCC also noted that allowing FXE and F7E as phone emissions and emission type FXD as a data emission “is unlikely to result in inharmonious emission types being used in the same segments of the frequency bands. We also conclude that allowing amateur stations to transmit these emission types is consistent with the basis and purpose of the amateur service, specifically to continue to contribute to the advancement of the radio art. We conclude that good cause has been shown for temporary waiver of Section 97.3(c)(5) to allow amateur stations to transmit emission types FXE and F7E as a phone emission and Section 97.307(f)(8) to allow amateur stations to transmit emission type FXD as a data emission. We therefore waive these rules accordingly, conditioned on the outcome of the pending rulemaking proceeding.”